Most asphalt shingles come 3 bundles to a square, and one square covers 100 sq ft of roof. A 30 × 40 ft house with a 6/12 gable roof and 12 inch overhangs has about 1,503 sq ft of roof, so it needs 16.5 squares, or 50 bundles of shingles. That includes 10% extra for cuts. Run your own house in the QtyLab roofing calculator.
How to figure bundles of shingles
- Footprint with overhang. Add the overhang to every side: a 30 × 40 ft house with 12 in overhangs is 32 × 42 ft = 1,344 sq ft.
- Multiply by the pitch factor. A sloped roof has more surface than the flat footprint. For 6/12 the factor is 1.118: 1,344 × 1.118 = 1,503 sq ft of roof.
- Convert to squares. 1,503 ÷ 100 = 15.0 squares.
- Add extra for cuts. 15.0 × 1.10 = 16.5 squares.
- Multiply by bundles per square. 16.5 × 3 = 49.6, round up to 50 bundles.
The pitch factor is √(1 + (rise ÷ 12)²). It works when every roof plane has the same pitch. If your roof has several pitches, add up each plane (length × slope length) and use the roof area mode instead.
Bundles of shingles by roof area
Roof area is the sloped surface, not the floor area of the house. 3 bundles per square, 10% extra, synthetic underlayment at 10 squares per roll, 4 nails per shingle. Click a size to open it in the calculator.
| Roof area | Squares to buy | Bundles | Underlayment rolls | Nails |
|---|---|---|---|---|
| 1,000 sq ft | 11 | 33 | 2 | about 2,900 |
| 1,500 sq ft | 16.5 | 50 | 2 | about 4,300 |
| 2,000 sq ft | 22 | 66 | 3 | about 5,700 |
| 2,500 sq ft | 27.5 | 83 | 3 | about 7,100 |
| 3,000 sq ft | 33 | 99 | 4 | about 8,500 |
Bundles of shingles by house size
Outside wall measurements, 6/12 gable roof, 12 in overhangs, 10% extra, 3 bundles per square. For a two-story house use the footprint, not the total living area. Pricing a 2,000 sq ft house? See how many squares is a 2,000 sq ft house.
| House | Roof area | Squares to buy | Bundles |
|---|---|---|---|
| 24 × 36 ft | 1,105 sq ft | 12.2 | 37 |
| 30 × 40 ft | 1,503 sq ft | 16.5 | 50 |
| 28 × 50 ft | 1,744 sq ft | 19.2 | 58 |
| 30 × 60 ft | 2,218 sq ft | 24.4 | 74 |
| 40 × 50 ft | 2,442 sq ft | 26.9 | 81 |
How roof pitch changes the count
Same 30 × 40 ft house, 12 in overhangs, gable roof, 10% extra. A steeper roof has more surface, so it takes more shingles.
| Pitch | Pitch factor | Roof area | Squares to buy | Bundles |
|---|---|---|---|---|
| 4/12 | 1.054 | 1,417 sq ft | 15.6 | 47 |
| 6/12 | 1.118 | 1,503 sq ft | 16.5 | 50 |
| 8/12 | 1.202 | 1,615 sq ft | 17.8 | 54 |
| 10/12 | 1.302 | 1,749 sq ft | 19.2 | 58 |
| 12/12 | 1.414 | 1,901 sq ft | 20.9 | 63 |
How much extra to buy
- About 10% for a simple gable roof.
- About 15% for a hip roof or a roof with valleys and dormers. Hips and valleys mean more cut shingles. The same 30 × 40 ft house with a 6/12 hip roof at 15% needs 17.3 squares, or 52 bundles, plus 5 bundles of ridge cap for about 106 ft of ridge and hips.
- Check the wrapper. Most architectural shingles are 3 bundles per square, but some heavy designer shingles take 4 or 5. The bundle label says how many sq ft it covers.
The rest of the roof materials
For the 30 × 40 ft house with a 6/12 gable roof, the calculator also works out:
- Underlayment: 2 rolls of synthetic (10 squares per roll, plus 10% for laps). #15 felt covers about 4 squares per roll and #30 felt about 2.
- Ice and water shield: 2 rolls for one 3 ft row along the 84 ft of eaves (a roll is 3 × 66.6 ft). In cold areas local code usually wants it to reach at least 24 in inside the wall line, which is often 2 rows. Valleys need extra.
- Drip edge: about 156 ft on the eaves and rakes, or 17 pieces at 10 ft with 5% for laps.
- Starter strip: 2 bundles (about 120 linear ft each, on eaves and rakes).
- Ridge cap: 2 bundles for 42 ft of ridge (about 25 linear ft per bundle).
- Nails: about 4,300. That’s 64 shingles per square × 4 nails, or 256 nails per square; use 6 nails per shingle (384 per square) where high-wind nailing is required.
Common mistakes
- Using the living area. A 2,000 sq ft two-story house might have only a 1,000 sq ft footprint. Measure the outside walls on the ground.
- Forgetting the overhang. 12 in on every side adds about 140 sq ft to a 30 × 40 house before pitch.
- Skipping the pitch factor. A 12/12 roof has about 41% more surface than its footprint.
- Counting starter and ridge as field shingles. Starter strip and ridge cap are separate bundles. Buy them by the linear foot, not by the square.
- Not checking bundles per square. Heavy designer shingles at 4 or 5 bundles per square change the count by a third or more.
- Ordering exactly to the number. Keep one or two unopened bundles back for repairs; many suppliers take back unopened bundles, but ask first.
What to buy for a 30 × 40 ft house (6/12 gable)
- 50 bundles of shingles (16.5 squares), plus 2 bundles of starter strip and 2 bundles of ridge cap. Buy these from a local roofing supplier or home center so the color and lot match; some deliver right to the roof.
- 17 pieces of 10 ft drip edge from the same supplier.
- 2 rolls of synthetic underlayment: shop synthetic underlayment
- 2 rolls of ice and water shield: shop ice and water shield
- About 4,300 coil roofing nails (one box of 7,200 covers it): shop coil roofing nails
- Cap nails to fasten the underlayment: shop cap nails
- Roofing nailer: shop roofing nailers
- Hook-blade utility knife for cutting shingles: shop hook-blade knives
- Roof jacks and a fall-protection kit for anything steeper than a walkable pitch: shop roof jacks · shop fall-protection kits
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More QtyLab calculators: the roofing calculator does squares, bundles, underlayment, drip edge, ridge cap and nails in one go. Painting the trim too? See how many gallons of paint do I need. Building a fence while you’re at it? See how much fencing do I need.
FAQ
How many bundles of shingles are in a square?
Most asphalt shingles are 3 bundles per square, and a square covers 100 sq ft of roof. Some heavy designer shingles take 4 or 5 bundles per square, so check the wrapper.
How many bundles of shingles do I need for a 30 × 40 house?
About 50 bundles for a 6/12 gable roof with 12 in overhangs. That’s 1,503 sq ft of roof, or 16.5 squares with 10% extra. A 6/12 hip roof at 15% extra needs about 52.
How many squares is a 2,000 sq ft house?
It depends on the footprint and pitch, not the living area. A one-story 40 × 50 ft house (2,000 sq ft) with a 6/12 gable roof and 12 in overhangs has about 2,442 sq ft of roof: 26.9 squares with 10% extra, or 81 bundles. A two-story 2,000 sq ft house has about half that roof. Full breakdown for a 2,000 sq ft house.
How many bundles of shingles for 1,000 sq ft of roof?
33 bundles. 1,000 sq ft is 10 squares; with 10% extra that’s 11 squares, and 11 × 3 = 33 bundles.
How many nails per square of shingles?
About 256 with 4 nails per shingle (64 shingles per square), or 384 with 6 nails per shingle where high-wind nailing is required. A 16.5-square roof takes about 4,300 nails at 4 per shingle.
Sources: GAF Timberline HD technical data (3 bundles per square, 4 or 6 nails per shingle); International Residential Code R905.1.2 (ice barrier to at least 24 in inside the exterior wall line where required). Estimates for planning only; confirm with your supplier and local code.